This invention relates to dispensing closures for containers and the combination thereof, and more particularly to single piece, push-pull dispensing closures for containers and the combination thereof.
Push-pull dispensers have been employed with a wide variety of products, including water, juices, condiments, and detergents. Push-pull dispensers enable the closure to be opened and closed without removing or separating any portion of the closure from the container, as well as providing other advantages. Thus, push-pull dispensers have gained widespread commercial acceptance.
Conventional push-pull dispensers are constructed from two interlocking pieces, including a bottom piece coupled to the container and a top piece slidably engaging the bottom piece. The bottom piece typically includes an circular member having a center hole, an upwardly depending skirt around the periphery of the hole, and a downwardly depending skirt connected to the outer periphery of the circular portion. The downwardly depending skirt includes threads that engage matching threads on the container. An elevated cylinder is disposed within the upwardly depending skirt that is supported by connectors.
The top piece includes an annular skirt having an upper and lower portion. The top piece has an orifice sized to engage the elevated cylindrical portion of the bottom piece to form a cap over the donut-shaped orifice of the bottom piece. The lower portion is sized is sized to fit over and slidably engage the upwardly depending skirt of the bottom piece whereby it can be raised and lowered. In its lower, closed position, the elevated cylinder plugs the orifice of the top piece to prevent discharging of the liquid contents within the container. In the upper, open position, the elevated cylinder disengages the orifice on the top piece to permit flow therethrough.
The two piece push-pull dispenser described above has disadvantages compared with single-piece screw-type detachable closures, including greater manufacturing costs associated with the two pieces and a smaller orifice and dispensing area. Further, because the top piece generally must be smaller than the outside diameter of the closure, the orifice is restricted, thereby causing a high velocity stream of liquid during dispensing which is undesirable in many applications, such as direct drinking from the closure.
U.S. Pat. No. 5,038,967 discloses a single-piece screw-type dispenser that employs a sealing ring having an inclined or frusto-conical outer sealing surface. The sealing surface engages an inner rim edge of the container neck. To provide a seal, the container neck contacts the rim edge only circumferentially along a thin portion of the scaling ring. To effectively provide the seal, the sealing ring must be urged tightly against the rim edge because only lightly contacting the frusto-conical sealing surface against the inner rim edge of the container would likely not provide adequate sealing because of manufacturing tolerances, slight burrs, and similar manufacturing and assembly irregularities. Thus, without inordinately tight manufacturing tolerances, the configuration of the '967 patent is not suitable for a push-pull closure because the treaded connection may be necessary to generate sufficient force to deflect or deform the sealing surface to provide continuous and repeatable sealing contact with the container neck.
U.S. Pat. No. 4,927,065 discloses an adjustable closure metering cap that may be configured either with a push-pull or a screw type action. The closure cap has a central metering post that includes slots, grooves, ramps, steps, or combinations thereof to provide various metered dispensing openings. Because the dispensing portion of the metering post is smaller than the container neck, and because the metered openings further constrict the dispensing flow rate, the closures disclosed in the '065 patent are not suitable where high flow rate is desirable. Further, the disclosure is primarily directed to two-piece closures which have the drawbacks described above.
U.S. Pat. No. 3,351,249 discloses a screw cap closure having an annular sealing portion that is insertable within the container neck. Because the apertures are disposed within the sealing portion, the area through which the product may flow is restricted.
It is a goal of the present invention to provide a push-pull dispensing closure from which a user may comfortably drink directly from or which may be used to dispense liquid by squeezing the closure at a desirably flow rate.